Inaccurate data transfer problem with hard drive housed in optical bay

So I've heard that 2011 MBPs are inconsistently compatible with 6mb/s hard drives in the optical bay, because the chipset was often 3mb/s. I had a 3mb/s drive in there and it worked like a charm. I put in a 6mb/s drive in and it works, but– for example– when I downloaded a movie, the file was somehow corrupted.

Now, I figured the problem was with the optical bay chipset (forgive me if that terminology is off), but it turns out that I have the Intel 6 Series 6mb/s connection, just like the one in the regular hard drive bay housing my SSD, which performs immaculately.

Some transfers work correctly, but intermittently I've been getting an error message that says: "The Finder can’t complete the operation because some data in “Some File” can’t be read or written. (Error code -36)"

Additional info: I use this aux drive to house all of my music, and it plays back without any problems that I'm aware of.

So what the !&&* is going on here? Why doesn't my drive work right?

the product number for my drive is:

ST2000LM007-1R8174